Britain's senior intelligence service, MI6, has briefed the Queen about secret video cassettes Princess Diana made three months after she wrote the letter in which she predicted she would be murdered in a car crash made to look like an "accident." She and her lover, Dodi al-Fayed, died in a car crash in Paris in August, 1997.

The royal briefing followed interviews with several British expatriates in California by a senior intelligence officer.

One of those questioned was involved in the London video-production industry at the time Diana made her video diaries. Another is known to have had "a close relationship" with a male member of the Kensington Palace staff when Diana lived there. The interviews came after MI6 became aware of Paul Burrell's new book. It may become the subject of a breach of copyright action centering on the letters it contains.

One security service source said her video diaries clearly show her "obsession" of meeting a stage-managed death at the hands of one of the intelligence agencies she believed were shadowing her every move since her divorce from Prince Charles.

Evidence to support her fears has been reinforced by the admission of America's "spy in the sky" agency, the National Security Agency, NSA, that it holds some 1,050 transcripts of conversations Diana made in the last weeks of her life.

But a former MI6 officer, Richard Tomlinson has also claimed that, while working for the service, he saw a document "that was a plan to murder the Serbian leader, Slobodan Milosevic-a plan that has unsettling parallels to the way Di and Dodi died. The MI6 document stated that the 'accident' should happen in a tunnel where the chance of injury is high."

The NSA tapes are stored in a climate-controlled vault at NSA headquarters at Fort George Meade outside Washington.

The agency controls a worldwide eavesdropping system normally only used against America's enemies.

Some of the taped conversations are said to refer to Diana's campaign for a global ban on landmines.

Dodi's father, Mohammed al-Fayed, the millionaire owner of Harrods, has waged an unsuccessful battle in the U.S. courts to obtain copies of the tapes.

He believes they will confirm his own fears of "intelligence service complicity" in the deaths of Diana and his son.

Ari Ben-Menashe, a former Mossad intelligence officer, who was approached by Mr Al-Fayed for help after the deaths said, "there is no doubt there was an intelligence presence in the run-up to their deaths".

Such claims will fuel the demand for a full inquiry into the events around the deaths.

The royal coroner, Dr. Michael Burgess, has al ready indicated he will hold an inquest. But no date has been set. At the earliest it could be sometime next year.

Friends of Diana have indicated the full truth may only emerge if there is a Hutton-style enquiry.

Diana filmed her secret video diaries on a camera her former voice coach, Peter Sutherland, gave her.

But he has no knowledge that the camera was used by Diana to make her video diaries.

Originally, he had made six tapes with Diana to help improve her confidence when speaking in public.

Sutherland has been trying to retrieve those tapes. Their existence emerged after the collapse of the Old Bailey trial of Paul Burrell last year.

He was acquitted on all charges of stealing Diana's belongings after the queen made a dramatic intervention in the case.